"""
/dms/utilities/profile.py

.. dient der Feststellung von Leistungsengpaessen
"""

class ProfileMiddleware(object):

    """

    Displays hotshot profiling for any view.

    http://yoursite.com/yourview/?prof



    Add the "prof" key to query string by appending ?prof (or &prof=)

    and you'll see the profiling results in your browser.

    It's set up to only be available in django's debug mode,

    but you really shouldn't add this middleware to any production configuration.

    * Only tested on Linux

    """

    def process_request(self, request):

        if settings.DEBUG and request.has_key('prof'):

            self.tmpfile = tempfile.NamedTemporaryFile()

            self.prof = hotshot.Profile(self.tmpfile.name)



    def process_view(self, request, callback, callback_args, callback_kwargs):

        if settings.DEBUG and request.has_key('prof'):

            return self.prof.runcall(callback, request, *callback_args, **callback_kwargs)



    def process_response(self, request, response):

        if settings.DEBUG and request.has_key('prof'):

            self.prof.close()



            out = StringIO()

            old_stdout = sys.stdout

            sys.stdout = out



            stats = hotshot.stats.load(self.tmpfile.name)

            #stats.strip_dirs()

            stats.sort_stats('time', 'calls')

            stats.print_stats()



            sys.stdout = old_stdout

            stats_str = out.getvalue()



            if response and response.content and stats_str:

                response.content = "<pre>" + stats_str + "</pre>"



        return response


